One person and one animal: Heartwarming? Slapstick? Living-together gags!

A huuuge rabbit with an over-all length of 2 meters suddenly appeared in his home? With his father in the middle of traveling, college student Reiichi decided to take care of this rabbit in his apartment that has a "No Pets Allowed" policy. With the majorly M rabbit UsaUsa, this majorly S pet owner might find....love? Living-together life...starts!

(Note: It's not clear without reading the manga if "Deka" refers to a detective (see Deka Wanko, for example) or if it's only short for dekai, meaning huge or gargantuan.)